Big Threats and Health Risks of Floodwaters

Big Threats and Health Risks of Floodwaters

What is Flooding?

 Flood is considered to be the most prevalent of all weather-related natural disasters. It can happen during various conditions: heavy and unceasing rain, when ocean waves come onshore, snow melts too fast, or even when dams break.

Flooding may occur with only a few inches increase in the water level or cover a house to its rooftop. It can happen quickly or occur over a long period, and it may last for days, weeks, or more.

The most dangerous kind of flood is the Flash Flood. It happens with the destructive power of a flood but with an unpredictable and implausible speed. Flash floods occur when excessive water fills normal arid creeks or river beds rapidly rise its water in a short period. It could happen just a little or without warning.

Where and when do floods occur?

Flooding is a hazard experienced by every household or business. It occurs in every territory and happens everywhere in the world that receives rainfall. In the U.S., floods kill people every year more than the hazard caused by hurricanes, lightning, and tornadoes, or any natural disaster.

It can greatly cause interruption of power, dislodgement of chemicals, water purification and wastewater disposal system, and spillover toxic waste sites previously stored above ground.

Albeit most of the floods do not create serious outbreaks of diseases or infectious illnesses and chemical poisonings, they can still cause infections to those who are contaminated with floodwater. Also, flooded areas may be surrounded by electrical or fire hazards with downed power cords; thus, overexposed floodwater is at risk.


Floodwater is not just ordinary accumulated rain. Most people are aware of the risk caused by it. It includes damage to property, destruction of crops, loss of livestock, and most of all, the deterioration of human health.
The water is usually contaminated with sewage with infectious substances and often hides harmful objects made of sharp metals or debris of broken glass. If a person has been exposed to floodwater, he will likely acquire skin diseases and other related illnesses. Floods have large social consequences for every individual and the for communities.
Even in the agricultural and industrial aspects, floodwater has massive impacts and threats. These hazardous chemicals or substances that are contaminated in the floodwater will cause several different health effects. Its signs and symptoms are most frequently associated with various diseases.
Big Threats and Health Risks of Floodwaters

Your Health Is At Risk!

Low floodwater or high floodwater can have devastating impacts not just on your home or family but extremely on your Health. If you get in contact with floodwater for a longer period, you must be alert that your health is at risk.

It poses various risks, which include contagious diseases, chemical hazards, and injuries. Floodwaters can potentially increase the transmission of the following infectious diseases:

Water-borne Diseases 

Flooding caused by hurricanes and normal rainfall can potentially increase the transmission of water-borne diseases. These diseases are transmitted through water that is contaminated with human or animal waste.

Because of the direct contact with this polluted water evident during the flood (floodwater), an increased risk of water-borne diseases may arise from wound infections or dermatitis to ear, nose, and throat infections. However, these diseases are not epidemic-prone.

Infections that are epidemic-prone are transmitted directly from contaminated water like zoonotic bacterial disease and leptospirosis. The transmission will potentially occur when there is a contact of the skin and mucous membranes to the mud contaminated with rodent urine or damp soil.

Flooding and excessive sewage resulting from the increased frequency of extreme weather events aggravate factors on the risk of waterborne diseases.

The excess of water can cause pressure on agricultural productivity, crop failure, malnutrition, starvation, population displacement, and resource conflict. Thus these scenarios impact the prevailing existence of waterborne disease.

Here are common waterborne diseases:

Vector-borne Diseases   

Vectors are common during floods. They are living organisms that can spread infectious diseases from human to human or from animal to human. Many of these vectors are parasitic insects that ingest disease-producing bacteria during a blood meal from an infected host (human or animal) and inject it into a new host during their next blood meal. The best-known disease vector is mosquitoes. Others include bugs, ticks, flies, sandflies, fleas, tritons bugs, and other freshwater aquatic snails.

These diseases are usually found in tropical and sub-tropical regions and places where access to safe drinking water and hygiene systems is difficult. Dengue is considered the world's fastest-growing vector-borne disease, with a 30-fold increase in disease incidence over the last five decades.

The standing water allows mosquitoes to breed uncontrollably. People are more susceptible when living in congested areas, increasing in the number when people sleep outdoors. One dilemma with floodwater is the inability to disperse the water because drains are blocked by plastic, garbage, and other debris. The water is stagnant for longer, which is one main factor of the widespread of diseases.

By expanding the number and range of vector habitats, floodwater may indirectly lead to an increase in vector-borne diseases. It is mainly caused by heavy rainfall or an overflow of rivers that may have acted as breeding sites for mosquitoes, enriching the disaster-affected population's potential for infections like dengue, malaria, and West Nile fever.

Flooding may have at first flush out mosquito breeding. Still, it comes back when the waters recede, and the interval time is typically around 6-8 weeks before the onset of a malaria epidemic.

Vectors and hosts involved in the conduction of these infectious pathogens are sensitive to climate change and other environmental factors. It mainly affects vector-borne diseases by influencing one or more of the following: vector and host survival, reproduction, development, activity, distribution, and abundance; pathogen development, replication, maintenance, and transmission; a geographic range of pathogens, vectors, and hosts; human behavior; and disease outbreak.

Summary and Assessment of Vector-borne Diseases    

Food-borne Disease 

Food-borne diseases include a wide range of illnesses and also growing public health all over the world. This is caused by the ingestion of foods contaminated with bacteria and other microorganisms or chemicals.

Malnutrition and hunger are typically the challenges faced by most developing countries. The United States and other developed countries still have significant populations greatly affected by inadequate food resources and are undernourished.

Food is considered to be the main source of food-borne illnesses. It usually resulted from eating spoiled food or food contaminated with microbes, toxic substances, or chemical residue from floods. Great weather events, such as flooding, scarcity, and wildfires, can contaminate crops and fisheries with chemicals, metals, and toxicants released into the environment. The possible effects of climate change on food-borne disease, nutrition, and security are mostly incidental, but on a worldwide scale, it can result in massive populations be greatly affected.

Foodborne Illnesses: What You Need to Know

Food-borne Illness and Disease  

Tips to Keep in Mind: Protect Your Home and Family

Before this kind of threat occurs, it is important to prepare your home and family in times of difficulties. Strong immune systems can get rid of the disease. A healthy diet and plenty of sleep are a must.

People should take preventive measures, and they should also work together to clean up their areas and dispel any stagnant water accumulated in the neighborhood.

Big Threats and Health Risks of Floodwaters

Drinking or eating anything contaminated by the floodwater can greatly cause diarrheal disease (such as E. coli or Salmonella infection). It is crucial to keep an eye on the health risk of disasters like flooding. To protect yourself and your family, these are the key points that you should bear in mind:

  • Citizens should take preventive medications. Boil water twice before drinking it. Wash all products with boiled water before cooking them. Food and water are equally essential to sustaining a person’s health when it comes to infections. Take note that food must be well-cooked and leftovers should be covered. Food waste must be disposed of appropriately. Food should not be eaten raw. Hands should be washed frequently with antibacterial soap, especially before eating.
  • Water is a basic necessity in our daily life. In drinking water, make sure that it is from a safe and reliable source. When you doubt where it comes from, you must boil the water for at least 10 minutes to make sure it's safe.
  • Do not walk or swim in floodwaters to shun diseases like leptospirosis. Dispose of all waste appropriately. You have to maintain good personal hygiene and put safety first. Refrain from getting close to hanging wires and unsteady structures. If possible, stay away from them.
  • Do not let children play with toys or any things that have been contaminated by floodwater or those that have not been sanitized or disinfected.
  • Take extreme caution with potential chemical and electrical hazards. They have great potential in causing fire and explosions. Floodwaters have the strength to move dangerous waste and chemical containers far from their usual storage places, creating a risk for those who come into contact with them. Any chemical hazards, like a propane tank, should be handled by the fire department or police.
  • Be sure you have your current tetanus shot before working in flooded areas. Wounds that are in contact with a flood should be evaluated for risk.

It is usually difficult to keep and maintain good hygiene during cleanup operations after a major flood.  To avoid floodwater diseases, it is important to wash your hands with soap and clean, running water, especially before work breaks, meal breaks, and at the end of the work.

Specified workers or concerned citizens in the area should take responsibility that any water in flooded areas is not safe unless the local officials or state authorities have specifically declared it safe and secure. If no safe water supply is available for washing, you may use bottled water, water boiled for at least 10 minutes, or chemically disinfected water.

If you suspect your water of being contaminated with harmful chemicals, cleanup workers may need to wear special chemical protective outer clothing, gears, and goggles. You should don plastic or rubber gloves, boots, and other protective clothing needed before getting inside a contaminated area that has been flooded to shun contact with floodwater. 

Using insect repellants or wearing long-sleeve shirts, long pants can decrease the risk of mosquito and other insect bites. Conscientiously wash your hands with the utmost care, using soap and water that has been boiled or disinfected before preparing or eating foods, after using the bathroom, after participating in flood cleanup activities, and after handling objects contaminated by floodwaters reduces the risk of infection.

Also, children should not be allowed to play in floodwaters or with toys that have been in contact with floodwaters. Toys should be disinfected. 

Flood water may have high levels of untreated sewage or other harmful substances. Primary symptoms from exposure to contaminated flood water may include intestinal problems, upset stomach, vomiting, headache, and other flu-like distress.

Once a person is experiencing these symptoms and any other problems related to this illness, he should immediately seek medical attention.

Related article for further reading about Floodwaters

 What do I do with my home septic system after a flood? 

 Protect children from a flood

Risk of waterborne illness via drinking water in the United States

Floodwater Fact Sheet 

Journal of Infectious Disease and Pathology   

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